. The cap is made from abrasion & dust-resistant glass with an anti-fingerprint coating. The quick-release design means that you can attach or detach it with ease. Abrasion & dust-resistant with an anti-fingerprint coating that protects against liquids. Tips. Attach the cap to the lens tightly or water may enter the device In the Box. Osmo Action Lens Filter Cap × 1. Specifications. Size Φ30.8 × 8.37 mm Weight 7.8 g. Compatible with Osmo Action..